A Brewing Water Chemistry Primer

[ajdelange]

The Primer assumes you are using water with low alkalinity (i.e. RO water or tap water diluted with RO to the point where the alkalinity is below 30). Thus the acid malt is there mostly to combat the alkalinity of the malt. Thus it doesn't matter how you sparge. The correct amount of acid malt is the amount that sets the mash pH correctly.

The 4% limitation is thought to be the level above which the sauermalz would render the beer tasting lactic. Sauermalz has a flavor effect at this level and below but that is generally thought to be a positive one by those who detect it but not all users do.

 

[Willum]

the acid malt is there mostly to combat the alkalinity of the malt. Thus it doesn't matter how you sparge. The correct amount of acid malt is the amount that sets the mash pH correctly.

Are you saying that the amount of water is irrelevant? I am not using RO water, but I have relatively low amounts of minerals in my tap water. I follow the primer, but I often add slacked lime in place of calcium chloride. I started by using the primer, but making the end result equal to what it would if I were starting with RO/DI water. The only mineral that I have more the 20ppm is chloride, so I add less of that. It works for me and my PH is steady. I am just questioning how adding 10 gallons of at mash in will change instead of adding 5.

My water report is below.

pH 7.3
Total Dissolved Solids (TDS) Est, ppm 157
Electrical Conductivity, mmho/cm 0.26
Cations / Anions, me/L 2.2 / 2.3
ppm
Sodium, Na 21
Potassium, K 1
Calcium, Ca 16
Magnesium, Mg 5
Total Hardness, CaCO3 61
Nitrate, NO3-N 0.2 (SAFE)
Sulfate, SO4-S 3
Chloride, Cl 42
Carbonate, CO3 < 1
Bicarbonate, HCO3 56
Total Alkalinity, CaCO3 46
Total Phosphorus, P 1.06
Total Iron, Fe 0.03
"<" - Not Detected / Below Detection Limit

My uneducated guess makes me think that the disparity is because of the bicarbonate in my water as compared to RO/DI water?

 

[ajdelange]

First observation is that slaked lime is a powerful alkali. If you add enough of it to pick up 40 mg/L calcium you are increasing the alkalinity of your water by about 100. That can be overcome by adding acid but you might as well just add calcium chloride or calcium sulfate instead of the hydroxide and then the acid.

Yes, the amount of water is a minor consideration if the water is soft (low in mineral content). The acid has to overcome the alkalinity of the malt and it has to overcome the alkalinity of the water. If the water contains little alkalinity then the amount of water doesn't matter much. If it contains lots then it does. You are right at the dividing line between low and moderate alkalinity so with your water you might find that you need a bit of extra acid if you mash in with the full volume rather than a subset.

 

[mabrungard]

Are you saying that the amount of water is irrelevant? I am not using RO water, but I have relatively low amounts of minerals in my tap water. I follow the primer, but I often add slacked lime in place of calcium chloride. I started by using the primer, but making the end result equal to what it would if I were starting with RO/DI water. The only mineral that I have more the 20ppm is chloride, so I add less of that. It works for me and my PH is steady. I am just questioning how adding 10 gallons of at mash in will change instead of adding 5.

Yes, changing the amount of water in the tun with the grist will affect mash pH. This is less true for really low alkalinity water, but is especially true as the tap water alkalinity rises. There is a limited amount of acid provided by the grist. There is X mg/L of alkalinity added with every drop of water in the tun. The acid quantity minus the total alkalinity added via the water drives the mash pH.

The BIAB method is a good case in point since typically the whole charge of water is added at once and the bag steeped. In this case, you assume that the mash water volume is the total water volume in contact with the grain and there is probably no (little??) sparge water.

I see that this water is pretty nice and I'm hoping that lime is only added in those cases where Bru'n Water says its really needed. As AJ says, its a powerful alkali. You definitely want the mash pH to end a little low than a little high. So an easy hand with the lime is important to avoid screwing a batch of beer.

 

[Willum]

I am using very small amounts of slacked lime. Just enough to get the water up to 50ppm calcium. I read in a few books that water with less then 50ppm can cause problems? It is often between 1-2 grams in 10 gallons of water.

First observation is that slaked lime is a powerful alkali. If you add enough of it to pick up 40 mg/L calcium you are increasing the alkalinity of your water by about 100. That can be overcome by adding acid but you might as well just add calcium chloride or calcium sulfate instead of the hydroxide and then the acid.

The reason I added the lime was in place of calcium chloride, to make for the fact that my water already had 42 chloride. It was not in addition to, but in place of. This of course is variable, based on how much chloride/calcium I am looking to end up with.

Yes, changing the amount of water in the tun with the grist will affect mash pH. This is less true for really low alkalinity water, but is especially true as the tap water alkalinity rises. There is a limited amount of acid provided by the grist. There is X mg/L of alkalinity added with every drop of water in the tun. The acid quantity minus the total alkalinity added via the water drives the mash pH.

This was my assumption, but I wanted to ask someone to confirm, thanks! Just so I have it right in my head, the "Total Alkalinity, CaCO3" is what we are talking about right? I assume because RO/DI water would have 0, less acid would be required to reach the same PH. As the volume of water increases so the does the acid requirement.

In this case, you assume that the mash water volume is the total water volume in contact with the grain and there is probably no (little??) sparge water.

In my case, no sparge water at all. This is a change for me, as I have always used a three vessel system and batch sparged. I want to go all electric and a 3 vessel system is just not in the cards.

 

[afr0byte]

I am using very small amounts of slacked lime. Just enough to get the water up to 50ppm calcium. I read in a few books that water with less then 50ppm can cause problems? It is often between 1-2 grams in 10 gallons of water.



The reason I added the lime was in place of calcium chloride, to make for the fact that my water already had 42 chloride. It was not in addition to, but in place of. This of course is variable, based on how much chloride/calcium I am looking to end up with.

Try using Bru'n Water to check what that does to your alkalinity (even in 10 gallons). For example, to raise my bicarbonate in 4.5 gallons of mash water to the 60s (for a dry stout) I only need about .5 grams of lime. You're likely adding more alkalinity than you want to add.

 

[mabrungard]

I am using very small amounts of slacked lime. Just enough to get the water up to 50ppm calcium. I read in a few books that water with less then 50ppm can cause problems? It is often between 1-2 grams in 10 gallons of water.

I'm hoping that you're adding lime only as needed to provide the alkalinity needed for your mash. Don't add it based on its calcium contribution or you are likely to add too much alkalinity to the mash and the pH could be too high. Using calcium chloride and calcium sulfate are the preferred additives to raise calcium content.

 

[mabrungard]

.

 

[Willum]

Try using Bru'n Water to check what that does to your alkalinity (even in 10 gallons). For example, to raise my bicarbonate in 4.5 gallons of mash water to the 60s (for a dry stout) I only need about .5 grams of lime. You're likely adding more alkalinity than you want to add.

According to Bru'n Water 1 gram in 10 gallons increases my calcium to 30.3 and my bicarbonate to 96.

 

[ajdelange]

This was my assumption, but I wanted to ask someone to confirm, thanks!

I think you are being led down the garden path a wee bit here. While in principal the amount of water does have an effect on pH in practice it is, for low alkalinity waters, small. Let's take your water and call its alkalinity 50 ppm as CaCO3 because that's a nice round number: 1 mEq/L. To move one L of that water to pH 5.4 will, assuming it comes to you at pH 7, require 0.9 mEq/L. Assuming that you put 455 g of malt in that liter of water (about 1 qt/lb) and that the malt had the typical buffering capacity of 25 - 30 mEq/pH-kg to move that malt from pH 5.8 to 5.4 would require 25*.4*455/1000= 4.55 to 5.46 mEq per pound of grain + liter of water for a total of about 5 (splitting the difference between 25 and 30 for the grain). The 0.9 for the water is about 15% of the total. That's what I meant when I said most of the acid goes to take care of the grain. Given a nominal buffering capacity for the grain of 27.5 mEq/kg-pH 0.9 mEq more of less of acid will move the pH of a pound of grain by 0.9/(27.5/2) = 0.06 pH. I'll leave it to you to decide whether that's significant or not. As I said, you are right on the borderline.

 

[ajdelange]

According to Bru'n Water 1 gram in 10 gallons increases my calcium to 30.3 and my bicarbonate to 96.

The molecular weight of Ca(OH2) is 74.093 grams/mol. One gram is thus 1/74.03 = 0.013508 or 13.5 mmol. Ten gallons is 37.854 L so that's 13.5/37.854 = 0.35 mmoL/L. As calcium's atomic weight is 40 mg/mmol that's 14 mg/L. With 16 mg/L calcium already in the water adding 14 gets you pretty close to 30 so check on the calcium.

OTOH your water has alkalinity of 46 which at pH 7.3 corresponds to a bicarbonate content of 53.5 mg/L. Adding 1 gram of Ca(OH)2 will raise the pH to 10.58 and in so doing convert bicarbonate to carbonate. The solution will be saturated with calcium carbonate some of which may or may not precipitate. You are effectively doing 'lime treatment' of your water. Your bicarbonate goes down but your alkalinity goes up to 80 (assuming there is no precipitation) while the bicarbonate actually goes down to about 26.

Many of the spreadsheets and calculators convert alkalinity to bicarbonate by

bicarbonate = 61*alkalinity/50.

This is OK if the pH is below 8 or so but, as in this case where the pH is higher, it's not that simple.

 

[Willum]

The molecular weight of Ca(OH2) is 74.093 grams/mol. One gram is thus 1/74.03 = 0.013508 or 13.5 mmol. Ten gallons is 37.854 L so that's 13.5/37.854 = 0.35 mmoL/L. As calcium's atomic weight is 40 mg/mmol that's 14 mg/L. With 16 mg/L calcium already in the water adding 14 gets you pretty close to 30 so check on the calcium.

OTOH your water has alkalinity of 46 which at pH 7.3 corresponds to a bicarbonate content of 53.5 mg/L. Adding 1 gram of Ca(OH)2 will raise the pH to 10.58 and in so doing convert bicarbonate to carbonate. The solution will be saturated with calcium carbonate some of which may or may not precipitate. You are effectively doing 'lime treatment' of your water. Your bicarbonate goes down but your alkalinity goes up to 80 (assuming there is no precipitation) while the bicarbonate actually goes down to about 26.

Many of the spreadsheets an calculators convert alkalinity to bicarbonate by

bicarbonate = 61*alkalinity/50.

This is OK if the pH is below 8 or so but, as in this case where the pH is higher, it's not that simple.

I am starting to understand why you recommend gypsum or calcium chloride to increase calcium. It does not increase the alkalinity, like Ca(OH)2 does. I am still taking this all in, but that seems like adding the lime, would be counter productive to what I am looking to achieve.

 

[emjay]

I am starting to understand why you recommend gypsum or calcium chloride to increase calcium. It does not increase the alkalinity, like Ca(OH)2 does. I am still taking this all in, but that seems like adding the lime, would be counter productive to what I am looking to achieve.

Pretty much. Lime is useful when you actually want to raise the pH due to a mash pH you determine is too low. But that's about it, and such beers are fairly uncommon.

 

[phoenixs4r]

/brag - about to get a free 5 stage filter with RO from my pops - /brag.

Now I just need a PH meter

 

[NanoMan]

New to this (impressive) forum and came here by way of discovering the EZ Water Calculator (how that happened I can no longer recall). Hate to start with taking as opposed to giving, but in the EZ WC raised the question: Assuming the mash is set as to pH and ions based on salt additions, is that the end of it? Or, should one care about the final ppm of the various ions resulting from the sparge water as well? For example, Ca may be 136 ppm in the mash, but when the sparge water volume is added into the mix it drops to 68. Certain beer styles rely heavily on ions for flavor character (IPA and SO4, for example). Any input would be appreciated.


NanoMan

 

[jmf143]

New to this (impressive) forum and came here by way of discovering the EZ Water Calculator (how that happened I can no longer recall). Hate to start with taking as opposed to giving, but in the EZ WC raised the question: Assuming the mash is set as to pH and ions based on salt additions, is that the end of it? Or, should one care about the final ppm of the various ions resulting from the sparge water as well? For example, Ca may be 136 ppm in the mash, but when the sparge water volume is added into the mix it drops to 68. Certain beer styles rely heavily on ions for flavor character (IPA and SO4, for example). Any input would be appreciated.


NanoMan

You've answered your own question. Use the PPM values after sparging to target the stylistic ion values to suit your tastes.

 

[ajdelange]

Get the mash pH right and you are pretty much free to 'salt to taste' beyond that. One thing you can do is add sulfate and chloride salts to finished beer to see if you think those additions improve or degrade the taste of the beer. If the former then add more either in the mash, to the sparge water or in the kettle. If the latter then figure out how, if possible, to remove the offending ion from your next batch.

 

[NanoMan]

Thank you both for the quck responses and the ideas. Gives me things to ponder.

NanoMan

 

[KaSaBiS]

Just to correct my understanding, using the Brun water spreadsheet to set up water profiles you select the region you want to emulate as far as sulfate, chloride and sodum, and you make minor adjustments in order to hit the right mash PH by adjustments.

I have essentially done this to a Hefeweizen a dunkelweizen, and a munich dunkel. the first two came out well, the 3rd is lagering and I am about to brew a Dortmunder export. in the spreadsheet it states a SO/Cl ratio of 2.5. So that tells me I need to bump up the chloride to get an appropriate ratio of 1.3 for this balanced malty/hoppy beer style. Should I really try and hit the 330 ppm sulfate amount or can I dillute it. Is the ratio more critical or high amount along with the ratio?

 

[afr0byte]

Just to correct my understanding, using the Brun water spreadsheet to set up water profiles you select the region you want to emulate as far as sulfate, chloride and sodum, and you make minor adjustments in order to hit the right mash PH by adjustments.

I have essentially done this to a Hefeweizen a dunkelweizen, and a munich dunkel. the first two came out well, the 3rd is lagering and I am about to brew a Dortmunder export. in the spreadsheet it states a SO/Cl ratio of 2.5. So that tells me I need to bump up the chloride to get an appropriate ratio of 1.3 for this balanced malty/hoppy beer style. Should I really try and hit the 330 ppm sulfate amount or can I dillute it. Is the ratio more critical or high amount along with the ratio?

I've never brewed a Dortmunder, so I can't provide specific numbers, but in general you want a lot of minerals in a Dortmunder.

 

[andycr]

I'm a beginner to water chemistry, but I sometimes use slaked lime when I simply can't get enough calcium any other way and don't want to resort to chalk. Pretty rare case though.

 

[KaSaBiS]

I've never brewed a Dortmunder, so I can't provide specific numbers, but in general you want a lot of minerals in a Dortmunder.

yeah. its pretty intimidating. So Since I was basiclly dilluting my existing profile to match munich's for the last few brews, then on the dortmunder profile it states a sulfate of 330ppm and Chloride 130ppm. going from 18/8 to 330/130 is pretty intense.

 

[thekage]

Delete please

 

[gizmodog51]

excellent info! with this and a water profile i can't go wrong!

GD

 

[DeltaRage]

How much does sauermalz malt reduce the pH of the sparge? How does this affect the sauermalz strategy for pH reduction?

Sparging with high pH water is associated with higher tannin extraction, so I'd like to lower the sparge pH. At the same time, the sauermalz malt strategy will surely leave some residual acidity that will lower the sparge pH. Because of this, it seems wiser to use lactic acid for both the mash and sparge water, because then one doesn't have to estimate the residual acidity left in the sauermalz malt. Does this make sense? Is there any benefit to using sauermalz malt instead of bottled lactic acid if they are the same thing, but the latter is easier to control for sparging (using a graduated dropper)?

Question for A.J.:

You recommend in the original post that one dilute water with RO or DI if there is high alkalinity. Can one not simply combat this with acid? My city water profile is as follows:

Calcium (Ca ppm): 35
Magnesium (Mg ppm): 9
Sodium (Na ppm): 14
Chloride (Cl ppm): 27
Sulfate (SO4 ppm): 28
Alkalinity (CaCO3 ppm): 124

 

[ajdelange]

There wouldn't be any excess acidity because one uses only enough acid to overcome the mash water and malt alkalinity. Thus the pH of the runoff will start to increase as soon as sparge water is added. The question is 'how fast?' It is entirely possible that you will be able to sparge to the desired level of runoff extract without breaking pH 6 and without using acid in the sparge water. It is pretty clear that you have a better chance of having things work out this way with DI or RO water than you would with highly alkaline water from some other source. To be absolutely safe you can acidify the sparge water to pH 6 or a little below. It should be clear that no amount of dilution will cause the pH to drop below 6.

You can acidify mash with sauermalz or acid but you should not acidify sparge water with sauemalz and you especially should not compute the amount of sauermalz required to acidify the sparge water and then add that to the mash as this would cause the mash pH to go too low. The big advantage of sauermalz, IMO, is the 1% w/w per 0.1 pH rule. This means no calculations you can't do in your head. A secondary benefit is that sauermalz is a specialty malt and conveys some flavors which are, IMO, beneficial to certain styles of beer.

The Question: Keep in mind that most of alkalinity comes from bicarbonate ion HCO3- and that this is disposed of when acid HAn with An representing the anion of the acid by

HAn + HCO3- ---> CO2 + H2O + An-

Thus every milliequivalent of bicarbonate removed by acid is replaced by 1 mEq of An-. In some cases this can be a benefit. For example, British brewers with low sulfate and chloride by high bicarbonate can replace the bicarbonate with sulfate and chloride ions from, respectively, sulfuric and hydrochloric acids. If, conversely, your water is high in sulfate, chloride and bicarbonate, neither sulfuric nor hydrochloric acid is a good choice for bicarbonate reduction. In such cases most brewers would probably use phosphoric acid as the phosphate ion is flavor neutral. Another popular choice is lactic acid but lactate is pretty strongly flavored and if a lot of bicarbonate has to be disposed of more lactate than is pleasing might be required.

The water cited has an alkalinity of 2.48 mEq/L. To get rid of most of it (2 mEq/L) would add 96 mg/L SO4-- if sulfuric acid were added or 70 mg/L chloride or some combination of less than those amounts of each totalling 2 mEq. Lactic and phosphoric amounts are a little harder to compute and it's late so I'm not doing it.

Another reason many favor dilution rather than acid addition is that if the source water is variable the amount of acid to be added is variable and can only be determined by measuring the alkalinity before each brew. A way around this is to simply add acid to the brewing water (no grains) until the pH reaches mash pH. That will get rid of about 80% of the alkalinity. Sierra Nevada does this, for example.

Remember that an important part of the primer is the KISS principle. Fiddling with acids, pH meters and alkalinity test kits is not part of the beginner's KISS approach.

Just to be sure the question gets answered the answer is not only yes, it can be done that way but that in fact many do.

 

[DeltaRage]

The water cited has an alkalinity of 2.48 mEq/L. To get rid of most of it (2 mEq/L) would add 96 mg/L SO4-- if sulfuric acid were added or 70 mg/L chloride or some combination of less than those amounts of each totalling 2 mEq. Lactic and phosphoric amounts are a little harder to compute and it's late so I'm not doing it.

Thanks for the reply A.J. It's very much appreciated.

I brewed a 5.5 gal batch immediately after my last message, so I didn't have a chance to read your message. I added some gypsum and a touch of calcium chloride, as well as 4.5ml of lactic acid to the water before I heated it and added it to the MLT. The spreadsheet said I'd hit around 5.46 pH with those additions (water only), which, when combined with malt, would result in a 5.46 - 0.25 = ~ 5.2 pH. After draining that off, I then added enough lactic acid to the sparge water to also hit 5.46 (before hitting the grain). Therefore, the mash and sparge pH, before they hit any malt, were the same. Was this reasonable?

As an aside, I need to treat the mash and sparge water separately unfortunately. But in adding roughly the same amount of lactic acid per gal, the pH of both the mash and sparge water should be the same before being added to the MLT. Next time I may split the gypsum and calcium chloride additions similarly so the mash and sparge water will be identical.

I'll invest in a pH meter soon so I can dial the pH in. I'll also try some acidulated malt next time (for the added flavour complexity), which I have plenty of here, but haven't used because I figured lactic acid additions would be easier.

Any suggestions?

Edit: I'm just realizing now that adding that much acid is going to change the flavour of the beer. What should I have done differently to ensure that the sparge water's pH isn't too high (other than dilution)?

 

[NanoMan]

I decided to add all of my salts to the mash, approximating as close as possible total water (mash, sparge etc.).
Here are some results from brews this weekend, room temp pH, theoretical pH as calcualted by EZWaterCalc:

Theoretical pH Actual Mash pH Post boil pH Post Ferment pH OG
Brown Ale 5.5 5.62 5.15 TBD 1.059

Stout 5.55 5.98 5.36 TBD 1.064

Helles 5.4 5.34 5.23 TBD 1.052


The darker beers came out with higher pH and the Helles with lower. More data (i.e., more brews!) is needed.

 

[ajdelange]

Are you putting chalk, bicarbonate or lime in your mashes?

 

[CDGoin]

Hmm.. I guess I am lucky..

All my water I got straight from the tap and the top-off water straight from the tap no boiling. No problems and beer so far tastes great.

That said our water is fairly soft and clean. I had aquariums and barely had to do anything to the water until after the fish were in it.